This study examined the time course of typing in prelingually and profoundly deaf as well as hearing individuals. Both groups of participants performed a written picture naming task and a written pseudoword task. Keystroke timing measurements from the written picture naming task revealed that the deaf as well as the hearing group were significantly delayed at syllable boundaries compared to identical within-syllable letter combinations. As the deaf are impoverished with respect to phonology based on spoken language experience, we postulate that syllabic segmentation is not crucially dependent on experience with spoken language. Furthermore, delays at syllable boundaries were not affected by word frequency in both groups, in contrast to the keys straddling a root morpheme boundary. Together with the finding that delays at syllable boundaries also occur in pseudowords, the experiments provide strong evidence towards post-lexical syllabification processes. Our results support previous findings which claim that (1) orthosyllables are autonomous and mode-specific entities, and (2) that the principles of syllabic organisation apply post-lexically.